tube rings very tight on OTA

[aqualand]

Hello all, hoping someone can help.

Ive got a Celestron Astromaster 130eq and find that rotating the OTA within the tube rings to be an absolute nightmare. The thumb screws have to be so loose they are virtually falling open and the scope is still difficult to move. Is this normal or should I have more play when loosening the screws?

Is this a known problem with this scope and does anyone have any ideas on how I could resolve this problem.

Thanks

[Bizibilder]

It may be one of the rings is distorted and is therefore gripping the tube? One solution is to wipe the scope tube over with a bit of "Mr Sheen" furniture polish - don't spray it just put some on a duster and wipe over. This will make the outside of the tube "slippery" and will last quite a while.

PS MrS is good stuff for all sorts of indoor "clean" lubrication jobs - curtain runners and door catches etc and it won't damage the furniture!

[Oily]

Have you checked the lining of the tube rings?Maybe some has 'doubled up' on itself so binding on the OTA?Another option is to buy a third ring and 'modify' it so it sits on the top tube ring so the OTA can't fall through if both tube rings are loose like this:

http://www.astro-baby.com/articles/rotating%20rings/Rotating%20Rings%20Project.htm

[ronin]

Having looked at the various images I would guess that the rings are simply intended to hold the scope and not designed with enough in hand to take rotation into account. Lets face it Celestron sell the system for around £170 so the rings will be fairly basic and for gripping the tube. Good tube rings could easily cost half of the whole scope price, and they are not going to supply ones of that standard. If looser then there will be a fair number that "complain" they are too loose. The old adage You cannot win.

If the scope is new then the felt could be too "thick", however the felt will compress over time so could enable rotation somewhat easier in say 6 months.

If you replaced the felt with a thinner variety it could loosen it all up now, but you may have to watch the situation later.

[aqualand]

Ronin, I see where your coming from with such a basic scope. I'll see if things do improve as the felt wears and look to get something thinner if need be.

Olly, I had actually just undertaken a more bodged approach to the link you provided using rubber tube and jubilee clips to try and keep the scope in balance when loosening the OTA rings.

Roger, that Mr Sheen trick seems to have solved the problem for now. Took the tube rings off, rubbed some around where the tube normally rotates and put it all back together, and now much easier to move and without having the loosen the thumb screws as much.

Thanks for all your replies.

[Siriusmeg]

I have the same problem with my astromaster, sometimes have to undo them completely. They are getting easier with use though. Like the Mr Sheen trick - I'll be doing that!